Earnest Luscombe prepared a resume of available data concerning Iris pumila. It began in The British Iris Society's Iris Year Book 1972 and continued for three issues. Despite its age it is reproduced here because of its excellence.Amongst Iris enthusiasts it is common knowledge that during the past twenty years or so the importance of this dwarf species of bearded cultivars, as a parent of miniature dwarf, standard dwarf and median hybrids. Iris pumila L. is also an excellent decorative garden plant in its own right, having regard to collected clones of the true species and garden-bred crosses between distinct types or color forms of the pure Iris pumila L. community. This applies to those growers whose garden is situated in a region where the altitude, soil and climate are particularly favourable: elsewhere it is not easy to establish as a perennial subject. In cultivation all forms of the true Iris pumila L. require to be grown in an open, sunny site, in fertile, somewhat fibrous, loamy soil with sharp drainage, although some growers are more successful in a sandy soil. In the case of a substantial, loamy soil plenty of grit such as limestone chippings should be well mixed with it. A rock garden where the general soil surface is sloping is a favorable plot, or the plant may be grown in a trough or deep granite sink in association with very dwarf or creeping alpine plants, where the iris can be kept fairly dry throughout winter. Fairly frequent transplanting is often advocated, but some dwarf specialists report that this species continues to grow and flower well over a period of several years in the same spot.The late Dr. Rudolph Hanselmayer is credited with the significant comment "The more yellow colour in the flowers the better grows the plant, both in nature and in the garden". Herr Eckard Berlin has produced a "Robusta" strain of Iris pumila L. which is a garden bred seed strain. I am attempting herein to present a clear concept of precisely what kind of plant, or community of plants, is encompassed by the species-name. Wm R. Dykes, in his standard monograph (1913) provided a fairly comprehensive description of one of the most familiar forms of this dwarf iris species which is furnished with an abbreviated flower-stalk and an elongated perianth-tube, most of which, together with the ovary, are enwrapped by closely investing and wholly or cheifly membranous spathes In his 1924 Handbook which was compiled largely for the benefit of the practical gardener, in order to emphasize the outstanding differences between the various dwarf Pogoniris species, Dykes has given a rigid delimitation of the morphology of I. pumila L. which, in the light of modern revelations as to the inherent variability of its morphology and inflorescence, is inadequate and misleading. For example, his statement that the spathes constitute a mere shapeless membranous wrapping is erroneous, seeing that in all forms the two separate spathe-valves are positively differentiated one from the other in size (in width particularly) and, although there is a preponderance of green-membranous tissue in the spathes of the most characteristic short-stemmed forms of I. pumila L. there are several other forms in which the outer valve, at least, is of stouter substance and is mostly green-herbaceous, usually with a distinct keel. The inner spathe-valve is in general more slender, more membranous, and often shorter than the outer valve. Sometimes the tips of the spathe-vales are of scarious tissue, dry membranous and brownish or whitish. The precise size and substance of each spathe-valve is of some importance in the task of identification and classification, especially in distinguishing I. pumila L. from other dwarf bearded species such as I. mellita, I. attica, I. chamaeiris and I. pseudopumila. In Dykes' Handbook 1924, page 196, it is stated that the inner chamber of the capsule (mature seed-pod) is trilocular in the upper part but that the lower one-half is an open undivided cavity. This is not characteristic, as in Julian Prodan's group which he entitled "Eu-pumilae" which includes "I. pumila typica" the capsule is trilocular as a rule, the inner dividing walls being joined from apex to base throughout the middle, although occassionally there is a quite small undivided central cavity of about 2 mm. in diameter. In those other forms of I. pumila L. in which the capsule has a large undivided cavity it is normally placed in the center, with the reduced inner dividing walls meeting each other both above and below the cavity. This is the case in Prodan's group "Orientales".The prominent recognizable characteristic of all forms of the true Iris pumila L. are its freely branching, segmented rhizome, the individual segments variable in length, shape and width; the consistantly dwarf and deciduous growth-habit of the plant; the elongated perianth tube; the standard segments of the perianth with a broad, usually ovate blade which is quite abruptly narrowed at its base to a very slender, stalk-like and fairly long haft; rather slender, clu-shaped or subspathulate fall segments which are adorned with an ample; dense beard; one single flowering shoot bearing one flower as a general rule, occassionally two flowers; and the ability of one rhizome to produce a lateral flowering shoot or shoots in addition to the terminal one; and the very considerable variation in attractive flower-colour and colour-patterns. The commonest, most typical forms possess an abbreviated flower-stem of from 5-15 mm. long, but in a few areas within its wide geographical range forms of the true species are found with stems up to about, 8, 10 or 12 cm. long. The substance or tissue of the spathe-valves is mostly green-membranous, although the outer valve may be partially herbaceous and keeled medially on the outside. The two valves closely enwrap and conceal the short stem, ovary and most of the perianth tube. Some writers suggest that in forms of I. pumila L. where the stem is very short it is a mere stump and that the ovary is virtually "sitting on" the rhizome. However, Julius Prodan reveals that certain specimens belonging to his group Eu-pumilae which grow in dry places and on sunny hills in Roumania, although the stem is only approximately 5 mm long it bears four leaves besides the two spathe-valves. The other kind within the group Eu-pumilae which is found on forested or woody hills in Siebenbuergen has a stem from 14 to 15 mm long with two nodes and internodes, and bears five leaves as well as the two spathe-valves, and the stem proper is separated from the ovary by an ovary stalk or pedicel of from 3-4 mm long. In some closely related species such as I. gurtleri Prodan the stem may be from 8 to 10 cm. tall with three nodes and internodes and may be conspicuously branched, bearing up to three flowers. One variant which has an elongated stem is I. pumila L. var. elongata Lipsky which has a stem of 12 cm. long. Intermediate stem-lengths are known, especially amongst Russian forms of the true species. It appears that no specimen of I. pumila L. has been discovered in which the stem exceeds 15 cm long.If we visualize I. pumila L. as a whole community or species-complex, we must recognize that most of its structural features are subject to some variation: size of plant, size of flower, colour of the flower, the lengtyh, breadth, shape and substance of each spathe-valve, length of stem, the number and size of the stem leaves; the length, width and texture of the basal leaves which subtend the stem, and of the leaves of the sterile fans; the length and precise form of the perianth-tube, size of ovary, the size, form and substance of the capsule and its inner walls and the extent of its undivided central cavity where this is present, and whether the seeds it contains are few or plentiful. Other less important features to be considered are the form, size and colour of the style-branches and their crests, the precise size and shape of the seeds, and the size and form of the segments of the rhizome and their pattern of development. The shape and size of the standard segments of the perianth varies rather markedly as between the distinct named varieties, but the outline of the fall segments shows a much less tendency to diversity. Coloration Two outstanding attributes are prominent in the case of I. pumila L. as distinct from all other dwarf bearded Iris species. These are (a) the conspicuous, infinite variation in flower-colour, color-blends and colour-patterns, and (b) the very extensive range of its natural geographical dispersal. The exceptional colour-variation sets it apart from any other bearded Iris whether dwarf or tall, and is probably unique in the Genus. A prominent spot or blotch on the blade of the falls is a common feature. The spot is often purple or brown, but not always, and the spot is not invariably darker than the prevailing colour of the flower; almost any two hues can be combined in this pattern. There is often a margin or "fringe" of different hue than the main colour of the flower. There are two basic lines of body colour, which are respectively yellow and violet or purplish, but these are subject to infinite, almost fantastic variation as to depth or intensity, and include pale creamy yellow besides deeper yellows, true blue, blue-purple, reddish-purple and very dark ruby, almost black. Blends are included, combining various colours with bronze, brown, pinkish, grey and green. Both amoena and variegata patterns are included, but no true plicata, nor a true self-pink with a tangerine beard has been discovered. A network of veining on the falls is often present, the colour of the veins being in contrast to the body-colour. Their is also much variation in the colour of the ample, dense beard, usually a combination of two colours, frequently either yellow, orange or white down the throat, and blue, or another hue as the beard extends outward on to the blade of the falls. Although it is fairly common to find flowers of a pale creamy yellow often with a greenish tinge on the falls, plants with really pure white flowers are rarely encountered. Dr. Rodionenko states positively that such plants do occur in Russian Moldavia, which tract of land adjoins the Roumanian border. In many instances the flowers have a perfume, which may be pronounced or quite delicate, and its quality varies. It may resemble that of violets, honeysuckle, heliotrope, orchid or vanilla. Sweet fragrance would seem to be especially common and well-marked in the forms which are peculiar to Dobrudscha Province in eastern Roumania. Certain well-informed authorities have suggested that the I. pumila L. population can be roughly divided into two parts according to the orientation of certain forms eastern forms as distinct from western forms but, having perused a wide selection of the literature, it seems to me to be a more realistic approach simply to emphasize that particular distinct morpological variations are met with in given regions or localities here and there over the vast geographical range of the species. Prodan's division of the Roumanian into Eu-pumilae and Orientales, however, appears to be justified, as the group Orientales is almost wholy confined to the easterly part of Roumania, from the Danube Delta southwards (Debrudscha) and the I. pumila L. forms which are indigenous there posess quite distinctive characteristics, especially as to capsules anmd seeds. One example (var. rozalie) occurs in Bessarabia, the adjacent part of the USSR. Dr. Rudolph Hanselmayer and others have stated that most forms of I. pumila L. from the USSR are distinguishable by their narrow flower-segments and slender leaves and other parts, and an especially elongated perianth-tube. .Amongst the Russiasn forms examples may be found with a stem from 7.5 to 10.7 cm tall occassionally bearing two flowers; and one Rodionenko collection No. 1574 consists of specimens with a stem from 5 to 12.7 cm long and the narrow, erect leaves may extend above the flowers, which are greenish-yellow with a smoothly "tailored" form, beard conspicuous, orange-tipped, and the blooms are borne on unbranched stems at a height of from 8 to 10 inches. Dr. Rodionenko himself has stated that whilst the I. pumila L. populations in the USSR are uniform in their general characteristics they do reveal variations in detail, with narrow or wide leaves, small or large flowers, early or late flowering, and attractive polychromism as in the more western lands of its over-all distributional range.. Mr. Welch in the 1953 Iris Year Book describes a very dainty form from Crimea with a very small violet flower with narrow segments. The perianth-tube is extra long and slender, and as the leaves are short and slim, and the spathe-valves are wholly green, neat and inconspicuous, the flower is well displayed above them.Professor L.F. Randolph has said (I.Y.B., 1955) that as far as its European extent is concerned the area of the natural dispersal of I. pumila L. is typically "Pannonian" that is, the species occupies lowlands of south-eastern Europe or, rather, climatically its especially favourable borders. .Elsewhere I. pumila L. is referred to as "a leading species of the Pannonian feather-grass steppes". More particularly it may be said that the natural geographic range of I. pumila L. is over south-central to south-eastern Europe including European Russia, besides which it is found in the Caucasus, Transcaucasia and to a limited extent in Asiatic Turkey (northern Anatolia) and in the extreme south-west of Asiatic Russia.AUSTRIA: especially the vienna basin. LOWER AUSTRIA: from Kalksburg to the Bruhl and Baden; in the Steinfeld; in the Laxenburg region; Leitha mountains; Hainburg hills; on the Bisamberg, near Ernst-brunn, Krems, Durnstein. CZECHOSLOVAKIA; cheifly southern Moravia (the northern limit of its range), Zanim, Pollau and Nikolsburg Hills, Auspitz, Brno, Kodan, Sokolnitz, hill of Pratz near Sokolnitz, Grumvirsch, Czeitsch, above Gumpoldskirchen, Paussam near Nikolsburg; and around Nitra in SLOVAKIA. ROUMANIA; Sisbenbuergen Province, especially its central and west-central parts; Cluj, Turda, Hermannstyadt, Muhlbach, Gross-Scheuern, Zackelsberg, Lagenthal; Bukovina Province to the north, Roumanian Moldavia in the north-east and in Dobrogea (Dobrudscha) in the extreme south-east beyond the Danube and from the Delta southwards. |